2,197 research outputs found

    Fully quantum state-resolved inelastic scattering of NO(X) + Kr: Differential cross sections and product rotational alignment

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    Fully quantum state selected and resolved inelastic scattering of NO(X) by krypton has been investigated. Initial Λ-doublet state selection is achieved using an inhomogeneous hexapole electric field. Differential cross sections and even-moment polarization dependent differential cross sections have been obtained at a collision energy of 514 cm^−1 for both spin-orbit and parity conserving and changing collisions. Experimental results are compared with those obtained from quantum scattering calculations and are shown to be in very good agreement. Hard shell quantum scattering calculations are also performed to determine the effects of the different parts of the potential on the scattering dynamics. Comparisons are also made with the NO(X)+Ar system

    Snout Shape in Extant Ruminants

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    Copyright: © 2014 Tennant, MacLeod. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. [4.0 license]. The attached file is the published version of the article

    Long-term visual outcomes after ruthenium plaque brachytherapy for posterior choroidal melanoma

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    BACKGROUND: To assess the long-term visual outcomes in patients with posteriorly located choroidal melanoma treated with ruthenium plaque brachytherapy between January 2013 and December 2015. METHODS: A retrospective review was conducted on consecutive patients treated with ruthenium plaque brachytherapy for post-equatorial choroidal melanoma with available Snellen visual acuity before and after treatment, and the development and treatment of radiation complications. RESULTS: There were 219 patients with posterior choroidal melanoma treated with ruthenium plaque brachytherapy. Median follow up was 56.5 months, range 12-81 months. Final visual acuity was ≥6/12 in 97 (44.3%) patients, 6/12 to 6/60 in 57 (26.0%), <6/60 in 55 (25.1%) and 10 (4.6%) eyes were enucleated. Radiation maculopathy was the most common radiation complication encountered, occurring in 53 (24.2%) patients. Of these, final visual acuity was 6/12 in 10 patients (18.9%), 6/12 to 6/60 in 26 (49.1%), <6/60 in 16 (30.2%) and 1 eye (1.9%) was enucleated. Twenty-five (47%) with radiation maculopathy were treated with intravitreal anti-angiogenic therapy, 27 (51%) were monitored and one (2%) was treated with scatter photocoagulation. Eyes treated with intravitreal anti-angiogenic therapy had better final vision than those observed or treated with retinal laser (chi-square, p = 0.04). On multivariate analysis, close proximity to the optic nerve and fovea, and large or notched plaque type was associated with final vision worse than 6/12. CONCLUSION: Most patients treated with ruthenium plaque brachytherapy for posterior choroidal melanoma retain 6/60 vision, with almost half retaining 6/12 vision at long term follow up

    Access to recreational physical activities by car and bus : an assessment of socio-spatial inequalities in mainland Scotland

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    Obesity and other chronic conditions linked with low levels of physical activity (PA) are associated with deprivation. One reason for this could be that it is more difficult for low-income groups to access recreational PA facilities such as swimming pools and sports centres than high-income groups. In this paper, we explore the distribution of access to PA facilities by car and bus across mainland Scotland by income deprivation at datazone level. GIS car and bus networks were created to determine the number of PA facilities accessible within travel times of 10, 20 and 30 minutes. Multilevel negative binomial regression models were then used to investigate the distribution of the number of accessible facilities, adjusting for datazone population size and local authority. Access to PA facilities by car was significantly (p<0.01) higher for the most affluent quintile of area-based income deprivation than for most other quintiles in small towns and all other quintiles in rural areas. Accessibility by bus was significantly lower for the most affluent quintile than for other quintiles in urban areas and small towns, but not in rural areas. Overall, we found that the most disadvantaged groups were those without access to a car and living in the most affluent areas or in rural areas

    A gentle introduction to the functional renormalization group: the Kondo effect in quantum dots

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    The functional renormalization group provides an efficient description of the interplay and competition of correlations on different energy scales in interacting Fermi systems. An exact hierarchy of flow equations yields the gradual evolution from a microscopic model Hamiltonian to the effective action as a function of a continuously decreasing energy cutoff. Practical implementations rely on suitable truncations of the hierarchy, which capture nonuniversal properties at higher energy scales in addition to the universal low-energy asymptotics. As a specific example we study transport properties through a single-level quantum dot coupled to Fermi liquid leads. In particular, we focus on the temperature T=0 gate voltage dependence of the linear conductance. A comparison with exact results shows that the functional renormalization group approach captures the broad resonance plateau as well as the emergence of the Kondo scale. It can be easily extended to more complex setups of quantum dots.Comment: contribution to Les Houches proceedings 2006, Springer styl

    Algorithms for Hierarchical Clustering: An Overview, II

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    We survey agglomerative hierarchical clustering algorithms and discuss efficient implementations that are available in R and other software environments. We look at hierarchical self-organizing maps, and mixture models. We review grid-based clustering, focusing on hierarchical density-based approaches. Finally we describe a recently developed very efficient (linear time) hierarchical clustering algorithm, which can also be viewed as a hierarchical grid-based algorithm. This review adds to the earlier version, Murtagh and Contreras (2012)

    The Sight Loss and Vision Priority Setting Partnership (SLV-PSP): overview and results of the research prioritisation survey process

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    Objectives: The Sight Loss and Vision Priority Setting Partnership aimed to identify research priorities relating to sight loss and vision through consultation with patients, carers and clinicians. These priorities can be used to inform funding bodies’ decisions and enhance the case for additional research funding. Design: Prospective survey with support from the James Lind Alliance. Setting: UK-wide National Health Service (NHS) and non-NHS. Participants: Patients, carers and eye health professionals. Academic researchers were excluded solely from the prioritisation process. The survey was disseminated by patient groups, professional bodies, at conferences and through the media, and was available for completion online, by phone, by post and by alternative formats (Braille and audio). Outcome measure: People were asked to submit the questions about prevention, diagnosis and treatment of sight loss and eye conditions that they most wanted to see answered by research. Returned survey questions were reviewed by a data assessment group. Priorities were established across eye disease categories at final workshops. Results: 2220 people responded generating 4461 submissions. Sixty-five per cent of respondents had sight loss and/or an eye condition. Following initial data analysis, 686 submissions remained which were circulated for interim prioritisation (excluding cataract and ocular cancer questions) to 446 patients/carers and 218 professionals. The remaining 346 questions were discussed at final prioritisation workshops to reach agreement of top questions per category. Conclusions: The exercise engaged a diverse community of stakeholders generating a wide range of conditions and research questions. Top priority questions were established across 12 eye disease categories. This is an Open Access article distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 3.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial

    Contemporary Evolutionary Divergence for a Protected Species following Assisted Colonization

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    Contemporary evolution following assisted colonization may increase the probability of persistence for refuge populations established as a bet-hedge for protected species. Such refuge populations are considered "genetic replicates" that might be used for future re-colonization in the event of a catastrophe in the native site. Although maladaptive evolutionary divergence of captive populations is well recognized, evolutionary divergence of wild refuge populations may also occur on contemporary time scales. Thus, refuge populations may lose their "value" as true genetic replicates of the native population. Here, we show contemporary evolutionary divergence in body shape in an approximately 30-year old refuge population of the protected White Sands pupfish (Cyprinodon tularosa) resulting in a body-shape mismatch with its native environment.Geometric morphometic data were collected from C. tularosa cultures raised in experimental mesocosms. Cultures were initiated with fish from the two native populations, plus hybrids, in high or low salinity treatments representing the salinities of the two native habitats. We found that body shape was heritable and that shape variation due to phenotypic plasticity was small compared to shape variation due to population source. C. tularosa from the high salinity population retained slender body shapes and fish from the low salinity population retained deep body shapes, irrespective of mesocosm salinity. These data suggest that the observed divergence of a recently established pupfish population was not explained by plasticity. An analysis of microsatellite variation indicated that no significant genetic drift occurred in the refuge population, further supporting the adaptive nature of changes in body shape. These lines of evidence suggest that body shape divergence of the refuge population reflects a case of contemporary evolution (over a 30-year period).These results suggest assisted colonization can introduce novel, and/or relaxed selection, and lead to unintended evolutionary divergence

    How paradata can illuminate technical, social and professional role changes between the Poverty in the UK (1967/1968) and Poverty and Social Exclusion in the UK (2012) surveys

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    © 2016, The Author(s). This article brings together analyses of the micro paradata ‘by-products’ from the 1967/1968 Poverty in the United Kingdom (PinUK) and 2012 Poverty and Social Exclusion in the UK (PSE) surveys to explore changes in the conditions of production over this 45year period. We highlight technical, social and professional role continuities and changes, shaped by the institutionalisation of survey researchers, the professionalization of the field interviewer, and economisation. While there are similarities between the surveys in that field interviewers were and are at the bottom of the research hierarchy, we demonstrate an increasing segregation between the core research team and field interviewers. In PinUK the field interviewers are visible in the paper survey booklets; through their handwritten notes on codes and in written marginalia they can ‘talk’ to the central research team. In PSE they are absent from the computer mediated data, and from communication with the central team. We argue that, while there have been other benefits to field interviewers, their relational labour has become less visible in a shift from the exercise of observational judgement to an emphasis on standardisation. Yet, analyses of what field interviewers actually do show that they still need to deploy the same interpersonal skills and resourcefulness to secure and maintain interviews as they did 45years previously

    Persistence of anticancer activity in berry extracts after simulated gastrointestinal digestion and colonic fermentation

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    Fruit and vegetable consumption is associated at the population level with a protective effect against colorectal cancer. Phenolic compounds, especially abundant in berries, are of interest due to their putative anticancer activity. After consumption, however, phenolic compounds are subject to digestive conditions within the gastrointestinal tract that alter their structures and potentially their function. However, the majority of phenolic compounds are not efficiently absorbed in the small intestine and a substantial portion pass into the colon. We characterized berry extracts (raspberries, strawberries, blackcurrants) produced by in vitro-simulated upper intestinal tract digestion and subsequent fecal fermentation. These extracts and selected individual colonic metabolites were then evaluated for their putative anticancer activities using in vitro models of colorectal cancer, representing the key stages of initiation, promotion and invasion. Over a physiologically-relevant dose range (0–50 µg/ml gallic acid equivalents), the digested and fermented extracts demonstrated significant anti-genotoxic, anti-mutagenic and anti-invasive activity on colonocytes. This work indicates that phenolic compounds from berries undergo considerable structural modifications during their passage through the gastrointestinal tract but their breakdown products and metabolites retain biological activity and can modulate cellular processes associated with colon cancer
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